Safety precautions as well as legal duties require many types and shapes of vessel surfaces to be periodically inspected for such problems as deterioration of wall thickness. Often these surfaces are insulated, requiring under present practice that inspection holes be cut through the insulation prior to each inspection and reclosed after each inspection. This laborious and costly operation could be simplified by the use of permanently cut inspection holes. Permanently cut inspection holes are usually not installed under present practice because satisfactory devices are not available which provide an acceptable weatherproof seal in the periods between inspections, which are easily installed and removed by inspectors, and which are applicable for a wide range of insulation consistencies ranging from the very soft types such as glass fibers to the hard types such as those made from silicates.
A practical, economical and dependable resealable sealing device for inspection port holes cut permanently in insulation is achieved by the present invention.